Mercurial > hg-stable
view mercurial/changegroup.py @ 4508:0026ccc2bf23
Remove atomicfile class.
The interface provided by opener(atomic=True) is inherently unsafe:
if an exception is raised in the code using the atomic file, the
possibly incomplete file will be renamed to its final destination,
defeating the whole purpose of atomic files.
To get around this, we would either need some bad hacks involving
sys.exc_info (to make sure things work in except: blocks), or an
interface to say "file is complete; rename it".
This is the exact interface provided by atomictempfile. Since there
are no remaining users of the atomicfile class, just remove it.
author | Alexis S. L. Carvalho <alexis@cecm.usp.br> |
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date | Tue, 05 Jun 2007 19:55:27 -0300 |
parents | e0793314360e |
children | 61462e7d62ed |
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""" changegroup.py - Mercurial changegroup manipulation functions Copyright 2006 Matt Mackall <mpm@selenic.com> This software may be used and distributed according to the terms of the GNU General Public License, incorporated herein by reference. """ from i18n import _ import struct, os, bz2, zlib, util, tempfile def getchunk(source): """get a chunk from a changegroup""" d = source.read(4) if not d: return "" l = struct.unpack(">l", d)[0] if l <= 4: return "" d = source.read(l - 4) if len(d) < l - 4: raise util.Abort(_("premature EOF reading chunk" " (got %d bytes, expected %d)") % (len(d), l - 4)) return d def chunkiter(source): """iterate through the chunks in source""" while 1: c = getchunk(source) if not c: break yield c def genchunk(data): """build a changegroup chunk""" header = struct.pack(">l", len(data)+ 4) return "%s%s" % (header, data) def closechunk(): return struct.pack(">l", 0) class nocompress(object): def compress(self, x): return x def flush(self): return "" bundletypes = { "": ("", nocompress), "HG10UN": ("HG10UN", nocompress), "HG10BZ": ("HG10", lambda: bz2.BZ2Compressor()), "HG10GZ": ("HG10GZ", lambda: zlib.compressobj()), } def writebundle(cg, filename, bundletype): """Write a bundle file and return its filename. Existing files will not be overwritten. If no filename is specified, a temporary file is created. bz2 compression can be turned off. The bundle file will be deleted in case of errors. """ fh = None cleanup = None try: if filename: fh = open(filename, "wb") else: fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg") fh = os.fdopen(fd, "wb") cleanup = filename header, compressor = bundletypes[bundletype] fh.write(header) z = compressor() # parse the changegroup data, otherwise we will block # in case of sshrepo because we don't know the end of the stream # an empty chunkiter is the end of the changegroup empty = False while not empty: empty = True for chunk in chunkiter(cg): empty = False fh.write(z.compress(genchunk(chunk))) fh.write(z.compress(closechunk())) fh.write(z.flush()) cleanup = None return filename finally: if fh is not None: fh.close() if cleanup is not None: os.unlink(cleanup) def readbundle(fh, fname): header = fh.read(6) if not header.startswith("HG"): raise util.Abort(_("%s: not a Mercurial bundle file") % fname) elif not header.startswith("HG10"): raise util.Abort(_("%s: unknown bundle version") % fname) if header == "HG10BZ": def generator(f): zd = bz2.BZ2Decompressor() zd.decompress("BZ") for chunk in util.filechunkiter(f, 4096): yield zd.decompress(chunk) return util.chunkbuffer(generator(fh)) elif header == "HG10UN": return fh raise util.Abort(_("%s: unknown bundle compression type") % fname)